Composite stencil-offset printing blank



Dec. 10, 1963 H. R. DALTON 3,113,511

COMPOSITE STENCIL OFFSET PRINTING BLANK Filed Sept. 27, 1951 2Sheets-Sheet 1 IN V TOR.

T BY Dec. 10, 1963 H. R. DALTON 3,113,511

COMPOSITE STENCIL OFFSET PRINTING BLANK Filed Sept. 27, 1951 2Sheets-Sheet 2 Z1 87 g? 22 in 20 AMP] l M 1 1 12 11 ABC RESISTANCEMERSURING INQT? INK ROLLERS WHTER ROLLER PRINTING FORM RUBBER TRANSFERROLL INVENTOR. HAROLD R DALTON @oy PAPER y%l% IMPRESSlON ROLL ATTO R NEV United States Patent 3,113,511 COMPGdlTE STENtIlL-OFFSET PRINTINGBLANK Harold R. Dalton, Rydal Road, lenkingtown, Pa. Filed Feb. 27, B61,Ser. No. 243,5@% 9 Claims. (Cl. 101-1492) This invention relates toduplicating blanks and more especially to electrosensitive blanks whichcan be used to produce a printing control plate or form, such forexample as is used in offset or planographic printing and the like.

The invention is in the nature of an improvement on the blank andprocess disclosed in my prior application Serial No. 755,263, filed lune17, 1947, now issued as US. Patent No. 2,664,043.

I have disclosed in said prior application a composite printed recordand stencil-forming blank, comprising a smooth-surfaced backing membersuch for example as smooth-surfaced paper, cardboard or other member,which is attached with a low degree of adhesive ailinity to anelectrically conductive plastic film so as to be readily mechanically ormanually peeled or stripped therefrom. The said plastic film is acarbon-bearing film which is normally non-porous, substantiallynon-hygroscopic, and has a smooth continuous surface, as distinguishedfrom the surface of a porous paper, fabric, or the like. When the blankis subjected to the action of stylus-applied electric voltagesrepresenting for example subject matter to be reproduced, the said filmis finely perforated through its entire thickness at the desired pointsbut without perforating the backing to which it is peelably attached.During the electro-perforation of the plastic layer, there issimultaneously deposited on the surface of the backing in registry witheach perforation a certain amount of carbon which thereby produces acarbon record of the signals which have simultaneously perforated theplastic film. Thus, if the signals are those representing printed,graphic or pictorial subject matter, there is simultaneously produced bya single electric recording operation a plastic film record stencilwhich may be used for duplicating purposes by any well-knownstencil-controlled process; and also there is produced on the backing acarbon copy of the stencilled record.

The surface of the paper, cardboard or similar backing member may berendered smooth and hydrophilic and substantially water insoluble byproviding it with a pigmented or non-pigmented coating containing asuitable binder, which binder is not affected by the subsequentapplication of the plastic film in liquid or semi-liquid form. Thus thepaper surfacing may be a pigmented or non-pigmented coating containingstarch, casein, polyvinyl alcohol or other similar binder which whendried on to the backing, produces a smooth and substantially waterinsoluble surface which surface however possesses hydrophilicproperties. By reason of the non-porous smoothed surface of the backing,the stencil-forming plastic film can be readily peeled from the backingby a simple manual peeling operation, without distorting, tearing ordestroying the said film. I have found that by incorporating a waterrepellent ingredient for example waxes such as chlorinated paraffin,octadecanoic amide, etc. in small percentage, for example between 3% andof film weight, into the plastic stencil-forming film, that theduplicate transferred carbon record on the surface of the backing isrendered selectively responsive to pick up printers ink such as is usedin ofset printing processes for example from a conventional inkingroller, the said transferred record being water-repellent orhydrophobic. The backing member from which the stencil film has beenstripped can then be used in any well-known offset printing machine orsimilar process to receive the usual print- "ice ing ink and it therebyserves as a master plate or form for making duplicate copies. Thus, bythe single electric recording operation there is simultaneously produceda plastic stencil which can be used in any well-known stencillingapparatus, and the backing from which the stencil is peeled, can be usedas a duplicating master printing form or plate.

The bacldng member with the simultaneously recorded carbon recordthereon is then used in any well-known offset printing apparatus wherebythe carbon record on the backing takes up the ink from the inkingelement of the printing machine, thus enabling the inked backing to beused as an offset or planographic printing form or plate. This avoidsthe necessity of forcing ink through the stencil openings while unpeeledfrom the backing, to form the printing plate or form as proposed inanother modification of the invention covered by the claims of myco-pending application Serial No. 292,700, filed June 10, 1952, nowabandoned.

Other features and advantages not particularly enumerated, will beapparent from a consideration of the following detailed descriptions andthe appended claims.

In the drawing,

FIG. 1 is a plan view of the novel blank containing a manually peelableplastic layer prior to performation thereof by received facsimilesignals.

FIG. 1a is a cross-sectional view of a modification of FIG. 1.

FIG. 2 is a view of the blank of FIG. 1 after perforation of the plasticlayer.

FIG. 3 is a sectional View of FIG. 2, taken along the line 33 thereof.

FIG. 4 is a view of the perforated plastic layer blank showing it in theact of being peeled from its backing.

FIG. 5 is a blank similar to that of FIGS. 1 to 4, and having areinforcing and stripping band at one end.

FIG. 6 is a cross-sectional view of FIG. 5, taken along the line 66thereof.

FIG. 7 is a view showing the blank of FIGS. 5 and 6, with the plasticlayer partially peeled from its backing.

PEG. 8 is a diagrammatic view of a facsimile transmit-ting andreproducing system for producing the facsimile stencil and printing formor plate according to the invention.

PEG. 9 is a diagrammatic View showing the blank of FIGS. 1 to 7 attachedto the drum of a conventional mirneograph machine.

FIG. 10 shows schematically a modified manner of using the recordedblank of FIG. 3 to produce an inked duplicate record on the backingmember prior to peeling the plastic layer. 1

FIG. 11 shows the plastic layer of FIG. 10, partially stripped from thebacking to exhibit the said inked record thereon.

FIG. 12 is a schematic diagram of one typical method of measuring thesurface resistance of the blank according to the invention.

FIG. 13 is a diagrammatic view showing how the duplicate record on thebacking is used in any well-known offset printing process.

FIG. 14 is a modification of FIG. 5.

FIG. 15 shows in magnified form or enlarged scale, a portion of thefinished offset printing plate produced according to the invention.

Referring to FIG. 1, the composite stencil and printing form accordingto the invention, comprises one or more integrally bonded layers of afilm-forming resin, plastic, or elastomer 3%, into the body of which isincorporated a predetermined amount of a powdered electrically-conducting material, such as electrically-conductive carbonblack, for the purpose of controlling the electric conductivity of thelayer it This layer it) is distinguished from ordinary carbon paper,since such ordinary carbon paper is electrically non-conductive for allpractical electro-recording purposes, whereas the layer according to thepresent invention has substantial electric conductivity which is usedfor the purpose of enabling the layer 10 alone to be perforated throughits thickness in response to stylus-applied electric signals. The layer10 is of a film-forming resin or plastic, such for example as thefollowing: Vinyl ester polymers, or reaction products of polyvinylalcohol and aldehydes, cellulose esters, ethers or the like; i.e., anyone of the well-known filmforming resins or elastomers such as vinylchloride polymers, vinylidine chloride polymers, vinyl chloride-vinylacetate copolymers, polyvinyl butyral polymers, styrene polymers,cellulose nitrate, cellulose acetate, ethyl cellulose, etc. In anyevent, the plastic film or layer is substantially non-porous with arelatively smooth continuous surface as distinguished from fibrousmaterial such as paper, fabric or the like. The layer 14 is applied ordeposited on a backing 11 of relatively stiff paper, cardboard, or thelike, and is applied for example by casting, roll coating, spraying,dipping, or brushing, so that it is directly but peelably attached witha low adhesive afiinity to the said backing 12. Preferably the backing"ill consists of any smooth-surfaced paper or cardboard such as thatknown as high-finish paper, machine glazed paper, or certain coatedpaper. The coating of paper 11 should consist of a pigmented ornon-pigmented coating and a binder chosen so as not to be affected bythe subsequent application of the stencil coating lil. As examples ofsuch binders may be mentioned, starch, casein, polyvinyl alcohol and thelike. This coating material applied to the surface of the paper backingshould also contain a substance which will make the coatingwater-insoluble after it is dried, but still allow it to retain itsdesired hydrophilic properties. For instance in the case of starchbinder, urea formaldehyde resin may be used. In the case of caseinbinder, formaldehyde can be used. Any other well-known method ofrendering the pigmented or non-pigmented coating water insoluble can beused so long as the said coating after it has become. dried will stillretain its hydrophilic properties. The backing member can be a flexiblemetal plate, having its surface prepared to make it hydrophilic, forexample by mechanical abrasion or other methods well-known in the artand as described for example in Gfifset Duplicator Techniques, byRichard Caruzzi, published by Harold L. Taylor Incorporated. If desired,the backing 11 may take the form of a cloth having a suitablesmooth-surfaced finish comparable to the papers described above. Inother words, the backing or carrier 11 may be of any sheet materialwhich will easily release the plastic coating or layer 10 after thelatter has been perforated by the received facsimile signals. Theplastic coating 19 is, in accordance with the invention, attached to thebacking 11 so that it can be peeled or stripped therefrom by simplestripping action, and without any destruction or deformation of thestripped film.

In accordance with the present invention, the plastic layer 10 isrendered electrically conductive so that when electric facsimile signalsare stylus-applied thereto, the plastic layer is perforated through itsentire thickness at each point underneath the stylus, but without anyperforation of the backing member 11. This results in the decompositionof the plastic with the concomitant deposition of the said decompositionproducts mainly as carbon on the backing. Such carbon is inherentlysubstantially hydrophobic. The electrical conductivity of the plasticlayer It can be regulated by incorporating therein a suitable quantityof colloidal electrically-conductive carbon. In order to intensify thesaid deposited decomposition products there may be incorporated in theplastic layer a small percentage, for example up to 10%, of a recordintensifying material. Typical of such materials are certain waxes, forexample chlorinated parafiin, octadecanoic amide, etc., or any otherwell known high molecular weight oleophilic material. The addition ofthese record intensify materials does not afiect the electricalconductivity of the plastic layer to an undesirable extent. The purposeof adding these record intensifying materials is to cause the carbonrecord that is simultaneously deposited on the surface of the backingmember to be intensified as compared with its deposition in the absenceof such materials, while being ink receptive and water repellent.

The invention is not limited to the formation of the plastic layer 19 asa single homogeneous layer. For example, it may be formed of one or morelayers or films of polyv nyl film-forming resin with each layercontaining different electrical conductivity characteristics. Thus asshown in FIG. 1a, if the backing 111 is of smooth-surfacednon-conductive paper, cloth, or cardboard, the plastic layer m can bemade of two superposed coatings Illa, lilb, of the above-mentionedfilm-forrning materials in which the coating lilo adjacent to thebacking 11 is designed to have the same or higher electric conductivity,in order to carry the recording current with as little loss in energy aspossible to the grounding strip or metal drum of the facsimile receivingmachine. Where two such superposed coatings are employed in the plasticlayer, special methods are used for keeping the two coatings fromintermingling. For example, a resin may be selected for the firstcoating lilo so that the solvent used for the resin of the secondcoating 19b does not have any effect upon the first coating. Instead ofusing different solvents for that purpose, the two coatings ltla, ltlb,may be cast as separate superposed films, the first film being cast anddried before superposing thereon the second film. It will be understood,of course, that the invention is not limited to a plastic layer lit ofdi ferent or graduated electrical resistance transversely of itsthickness, and a singlelayer homogeneous film of uniform or homogeneoustransverse resistance may be employed. If desired, the backing 11 may berendered electrically conducting itself, or it may be in the form of ametal foil such as aluminum foil or electrically-conducting paper, inwhich event a correspondingly lower electrical conductivity may beemployed in the plastic layer 10.

Preferably the exposed surface of the plastic film It (FIG. 1), or thelayer 2% (FIG. la), is provided with a whitish masking coating 12 ofextreme thinness, just sufiiciently thick to mask the dark color of theplastic coating id. For typical examples of such masking coatlugs andtheir preparation, reference may be had to said US. Patent No.2,398,779, issued April 23, 1946. In any event, the plastic film orcoating 16 is so designed that when it is acted upon by the electricalsignals stylusapplied thereto, it results only in perforation of theplastic film and its masking coating 12, and without any perforation ofthe backing 11. This relation is shown in FIGS. 2 and 3 of the drawing.

After the recording has been effected by perforating the plastic layerand its masking layer 12, said layer together with its contrastingmasking coating is then peeled from the backing 11, as indicated inFIGS. 4 and 7. Because of the low adhesive affinity between the plasticfilm and the backing 11, this stripping or peeling action can beeffected without any special tools, and without any damage to theperforated plastic film. This perforated plastic film containing therecorded subject matter can then be mounted on the drum of anywell-known stencilcontrolled machine to produce any desired number ofcopies. Since the perforated plastic record blank is of non-porousmaterial, it does not lose its surface characteristics even after agreat number of copies have been made. Furthermore, since it is ofplastic, it can be smoothly and family attached to the drum of theduplicatmg machine and without crinkling or bulging, as is likely withconventional paper or similar stencil sheets.

In order to facilitate the peeling of the perforated record plasticlayer 16 from the backing 11, that layer may have attached integrally tothe exposed surface thereof, at one end, a reinforcing strip 13 of heavypaper, cardboard, or other material, or if desired, the plastic layeritself may be doubled or thickened at this portion so as to provide areinforcement and gripping edge to facilitate peeling, as illustrated inFIG. 7 of the drawing. It has been found that when the stripped plasticstencil has been mounted on the usual stencil-controlled printing drumor the like, after continued rotation the stencil sheet tends to skewitself on the drum, or to become distorted at one or both longitudinaledges. I have found that these objections can be overcome by applying toeither or both longitudinal edges of the stencil blank, prior to recording thereon, strips 13a, 13b, as shown in FIG. 14. If desired, whenthe strips 13a, 13b, are used, the end strip 13 may be omitted.

Referring to FIG. 8, there is shown in schematic form a typical methodof perforating the blank of FIG. 1 in accordance with electric signals.Thus there is shown in the left-hand portion of FIG. 8 a conventionalfacsimile transmitter comprising a scanning drum 14- which is adapted tobe rotated at a suitable speed by a motor 15, and also simultaneouslyfed longitudinally of its axis, for example by a lead screw 16 and splitnut 17. The fac simile subject matter in the form of a sheet or film 18is wrapped around drum 14. Associated with the drum is a scanning headof any well-known construction comprising a scanning light source 19 anda photoelectric cell 20 for translating the shades of the successiveelemental areas of subject 18 into corresponding electric signals. For adetailed disclosure of one form of scanning drum and associatedmechanism, reference may be had to US. Patent No. 2,138,784, grantedNovember 29, 1939. These signals are then applied to modulate an audiofrequency carrier from the carrier source 21 through the amplifiermodulator unit 22. At the receiving station shown in the right-handportion of FIG. 8, there is provided a metal and electrically-groundedscanning drum 2.: which may be similar to drum 14. Drum 23 is arrangedto be driven in rotational and longitudinal synchronisrn with drum 14 bymeans of a motor 24 and a lead screw 25. The recording blank such as theblank of FIGS. 17 is wrapped around drum 23, and cooperating with thisblank is a recording conductive stylus 26 which is supplied withelectrical energy from the receiving amplifier 27, preferably, althoughnot necessarily, through a transformer 28 whose secondary windingenergizes stylus 26. By reason of the character of the recording blankon the drum 23, these electric signals cause the 10 to be perforated inlocalized areas corresponding to the original subject matter on thetransmitting blank 13 but without perforation of the paper backing 11.When the recording has been completed, the blank is removed from drum23, and the stenciled film or strip 10 is stripped from its backing 11.This stenciled strip can then be used to duplicate the recording by anywell-known duplicating process. Because of the porous nature of thestencil only at the areas where the recording takes place, duplicationby ordinary stencil-controlled printing processes can be employed. Sincethe blank is only perforated at the regions where the recording takesplace, its over-all strength is not greatly reduced, and therefore itmay be handled with ease.

FIG. 9 shows, in diagrammatic form, a portion of a typicalstencil-controlled printing machine comprising the usual drum 29 havingthe usual blank-clamping member 30 and supporting screen under thestencil. The perforated record blank above described is partially peeledat one end, as shown in FIGS. 4 and 7, and the peeled plastic film atits reinforced end is clamped to the drum 29. The backing member 11 canthen be completely peeled away from the plastic film, as indicated inFIG. 9. The reinforcing strip 13 above described, prevents distortion ofthe plastic film during this peeling process, and also prevents theclamping means 30 from harming the said plastic film during the clampingthereof to the mimeograph drum. While as mentioned hereinabove with theblank of FIGS. 1 to 7, when the plastic layer is perforated by thesignals, it results in the production of a corresponding positive copyon the surface of the backing 11. This copy consists of the carbonparticles which have been transferred to the surface of backing 11during the recording process. If desired, this record on the backing 11can be made into an inked record, as indicated schematically in FIG. 10,by applying a layer of ink 31 to the recorded blank, and by means of asqueegee or similar device 32 the ink 31 can be forced through therecorded perforations in the plastic layer to form a correspondingpositive inked record on the backing 11, so that when the plastic layeris stripped therefrom, as shown in FIG. 11, a corresponding permanentinked record appears on the backing 11. This backing 11 may then be usedas an offset printing plate for use in any well-known offset printingmachine, or hectograph machine.

I have found that by treating the surface of the backing member 11 so asto render it hydrophilic while rendering it Water insoluble and byincorporating the said waxes in the plastic film, the carbon recordwhich is deposited on the backing member during the electrorecordingoperation is of sufficient intensity so that the backing member with thecarbon record can be used directly as an offset printing form withoutthe necessity of squeegeeing ink through the perforations of thestenciled film. In other words, the stenciled film can be stripped fromthe backing and used as a stencil and the backing with the carbon recordcan also be used as a separate offset printing form, as indicated inFIG. 13.

While the invention is not limited to any particular thickness for theplastic film and its masking coating, since the blank must respond toconventional facsimile signals, and since these signals are forpractical purposes of limited voltage range, it is important that themasking coating 12 be of the minimum thickness consonant with itsmasking qualities for the darkened plastic film 10. I have found thebest results to be obtained when the combined thickness of the plasticfilm 1% with its masking coating 12, or the combined thickness of thefilms 10a, 10b, with the masking coating 12, does not exceedapproximately 0.006 inch, and preferably should be between 0.001 inchand 0.003 inch. Preferably also,

the blank should have a surface resistance of approximately 1,000 to8,000 ohms before the top coating is applied. With this relation ofresistance and thickness, conventional facsimile signals can bestylus-applied to the blank, to perforate it Without burning orperforating the cardboard backing 11. Furthermore, as the plastic layer19 is thus perforated, it results in the deposition of carbon on thesurface of the backing 11 beneath each perforation, thus producing adirect duplicate and permanent record in the form of deposited carbon onthe surface of the said backing 11. In other words, by this processthere are produced at the same time, a perforated plastic sheet recordof the facsimile subject matter, and also a carbon-deposited record onthe surface of the backing 11. One convenient way of measuring thisresistance is shown in FIG. 12. A strip of the record blank, for examplenine centimeters long by three centimeters Wide, has clamped thereto apair of flat electrodes, each one centimeter in length and spaced apartby one centimeter, and located at the central region of the strip. Theseelectrodes are connected to a suitable resistance-measuring instrument,such for example as a Wheatstone bridge or ohmmeter.

While certain particular embodiments have been disclosed herein, it willbe understood that various changes and modifications may be made thereinwithout departing from the spirit and scope of the invention.

This application is a continuation-in-part of application Serial No.755,263, filed June 17, 1947, and of application Serial No. 188,702,filed October 6, 1950, now abandoned.

The term plastic is employed in the claims in a generic sense to includefilm-forming resins and elastorners.

For a typical formulation for the conductive plastic coating referencemay be had to Patent 2,664,043; and for a typical formulation for thelithographic coating on the backing, reference may be had to US. Patent614,029.

By the expression intensifying ingredient as used herein is meant amaterial which when incorporated together with powdered carbon in theperforatable stratum attached to the backing, produces on said backingdecomposition products when said stratum is subjected to a perforatingelectric discharge, which products have a more intense blackness than isproduced by the perforation of said stratum containing powdered carbonwithout such ingredient. In either case the carbon deposit isink-receptive and hydrophobic except that in one case, namely with theintensifying ingredient in the plastic, it is blacker and more intense,and is a more effective ink receptor.

What is claimed is:

1. A blank of the kind described, comprising a flexible backing havingits surface treated to make it a lithographic surface which is waterinsoluble and hydrophilic, and a layer of plastic adhesively attached tosaid surface, said layer containing powdered carbon to render it anelectric conductor and being attached to said backing with a low degreeof adhesive aflinity to facilitate its manual peeling therefrom withouttearing and Without permanent deformation.

2. A blank for producing a facsimile lithographic record under controlof electric voltages applied to the blank comprising, in combination, abacking member having a smooth, Water insoluble, hydrophilic,lithographic surface, a plastic film adherently attached to saidlithographic surface of the backing with a low degree of adhesiveaffinity so as to be readily strippable therefrom manually when dry, theplastic of said film being normally a non-conductor but havingincorporated therein prior to attachment to said backing a quantity ofconductive carbon to render the film perforatable by said appliedelectric voltages and to simultaneously deposit on said lithographicsurface corresponding ink-receptive areas consisting of thedecomposition products of the perforated plastic.

3. A blank according to claim 2, in which said litho- 9 graphic surfaceon the backing contains a filler and a binder which does not have itshydrophilic character affected by the subsequent adherent application ofsaid plastic film thereon, nor by the subsequent stripping of theplastic film therefrom.

4. A blank according to claim 2, in which said plastic film is comprisedof at least two strata of different electric conductivity with thestratum of higher conductivity adjacent the said backing.

5. A blank according to claim 2, in which said plastic film hasincorporated therein a wax constituting up to 10% of the Weight of thefilm but Without substantially affecting the electrical conductivity ofsaid film.

6. A blank according to claim 2, in which said plastic film has alsoincorporated therein with said carbon a decomposition productintensifying ingredient to intensify the said deposition products on thebacking when said plastic film is perforated by an electric discharge.

7. A blank according to claim 6, in which said intensifying ingredientis in the form of a high molecular weight oleophilic material.

8. A blank according to claim 7, in which said oleophilic material is achlorinated paraflin.

9. A blank according to claim 7, in which said oleophilic material isoctadecanoic amide.

References (Iited in the file of this patent UNITED STATES PATENTS915,680 Kosters et al Mar. 16, 1909 1,221,780 Wald Apr. 13, 19171,656,338 Ranger Jan. 17, 1928 2,140,483 Schutte Dec. 13, 1938 2,142,250Neidich Jan. 3, 1939 2,156,100 Simons Apr. 25, 1939 2,230,981 Toland etal Feb. 4, 1941 2,294,146 Wise Aug. 25, 1942 2,342,713 Wescott Feb. 29,1944 2,346,812 Bradner Apr. 18, 1944 2,351,696 Nichols June 30, 19442,385,562 Baczewski Sept. 25, 1945 2,398,779 Dalton et al Apr. 23, 19462,402,469 Tuland et al June 18, 1946 2,419,206 Fischer Apr. 22, 19472,500,617 Meigs Mar. 14, 1950 2,503,679 Newman Apr. 11, 1950 2,540,125Van Dusen Mar. 13, 1951 2,664,043 Dalton Dec. 29, 1953 2,713,822 NewmanJuly 26, 1955

1. A BLANK OF THE OF THE KIND DESCRIBED, COMPRISING A FLEXIBLE BACKINGHAVING ITS SURFACE TREATED TO MAKE IT A LIGHOGRAPHIC SURFACE WHICH ISWATER INSOLUBLE AND HYDROPHILIC, AND A LAYER OF PLASTIC ADHESIVELYATTACHED TO SAID SURFACE, SAID LAYER CONTAINING POWDERED CARBON TORENDER IT AN ELECTRIC CONDUCTOR AND BEING ATTACHED TO SAID BACKING WITHA LOW DEGREE OF ADHESIVE AFFINITY TO FACILITATE ITS MANUAL PEELINGTHEREFROM WITHOUT TEARING AND WITHOUT PERMANENT DEFORMATION.